Patent Application
20230068480
The application relates to pavement markers, and particularly to temporary flexible pavement markers.
During highway construction and repair, it may be necessary to route traffic over streets that are incomplete or undergoing reconstruction. During such operations, it is not unusual for accidents to occur in work zones where the edges of the traffic lanes are not clearly marked. This is especially true in the construction of new roads between the time that a subsurface is laid down and the final application of asphalt.
Periodic road maintenance normally includes pavement resurfacing using either a chip, slurry, or road seal compound that is applied over the original surface to restore and protect it. When this is done, the existing painted traffic lines, be they centerlines, passing lines, no passing lines, turn lane lines, or any other traffic painted line will be covered and thereby obliterated and no longer visible.
Even after asphalt is applied to a road surface, is not unusual for there to be a period of time between the application of the asphalt and the installation of permanent lane markers. One solution to this problem is the use of temporary pavement markers. These temporary pavement markers are typically formed of a resilient plastic material having a base portion and an upwardly extending reflective portion that will extend up through each coating applied to the road surface during the pavement operation. Such temporary pavement markers are typically designed to last long enough for the entire resurfacing project to be completed, and up to and including the repainting of the various traffic lines upon the new surface. It would be desirable in the art of highway construction and maintenance to be able to employ temporary flexible pavement markers that may be installed and ready for use in a single step.
A temporary flexible pavement marker may comprise a base configured for mounting to a road surface, a stand flexibly extending substantially perpendicularly from the base, the stand comprising a reflective portion not covered by any protective layer removable therefrom, and a protective shield extending from the stand above the reflective portion such that when the marker is installed on the road surface, the protective shield substantially shields the reflective portion from being obscured by fluid material sprayed down onto the road surface but does not substantially obscure reflection of light from the reflective portion to vehicles traveling on the road surface after the fluid material has been sprayed down onto the road surface.
In one embodiment, a temporary flexible pavement marker may comprise a base, a stand and a protective shield wherein at least part of the stand is reflective (either of itself or because of having a reflective tape attached thereto or a reflective paint applied thereon); The protective shield is configured to substantially prevent materials, such as asphalt, tar, oil, and water, that may be sprayed down upon the temporary flexible pavement marker from obscuring the reflective part of the stand.
Turning to
In some embodiments, the base 106 is configured for mounting the marker 100 to a road surface (not shown). In one embodiment, the mounting surface 112 of the base 106 may include one or more ridges 114. In some end uses of the temporary flexible pavement markers of the application, it may be desirable to retain a fluid such as tar or asphalt or epoxy other adhesive to improve the adhesion of the temporary flexible pavement marker to the pavement. The presence of ridges 114 serves to facilitate the retention of such fluid. In other embodiments, the mounting surface 112 of the base 106 may be hatched, or grooved, or provided with a roughened texture so as increase the surface area and thus improve adhesion to the surface on which the marker 100 is to be bonded. In yet other embodiments, any combination thereof may be used to better configure the mounting surface 112 for mounting to a road. Of course, the mounting surface 112 may also be smooth.
The protective shield 102 may be disposed at or near the upper terminus of the stand 104 and extend from the stand 104 to provide protection from spray originating from above the marker 100. In the embodiment of
The protective shield may comprise a non-removable portion of the temporary flexible pavement marker, and may comprise the same material as the rest of the temporary flexible pavement marker. The protective shield may comprise any suitable thickness sufficient to maintain the protective shield, under a variety of typical road temperature conditions, in an orientation substantially shielding the reflective surface from spray delivered down to the road surface over the marker.
In some embodiments, a drip edge 103 of the protective shield may comprise a squared edge, a radius or a sharp edge. The protective shield 102 may be substantially normal to the stand 104 to create a “T”. In the embodiment of
The stand of the temporary flexible pavement marker may be at least partially reflective. In some embodiments, the reflective portion of the stand may be prepared by applying thereto a reflective tape or a reflective paint. In other embodiments, the stand itself may be formed of reflective material. The term “reflective” means that the subject surface is either retro reflective or prismatic to the extent that the temporary flexible pavement markers are sufficiently responsive to automobile headlights to safely delineate a traffic lane at night or other dark or limited-visibility driving conditions.
In the embodiment of
In some embodiments, a secondary protective rib 110 may be provided on the stand 104 to prevent back splashing from the surface of the road. The secondary rib 110 may run the entire length of the marker 100. Alternately, the entire rib 110 may comprise a series of rib sections along the length of the marker 100. In some embodiments, the series of rib sections may be spaced such that the surface tension of droplets and surface friction on the secondary rib sections prevents the droplets from passing beyond the secondary rib in which the secondary rib sections act much like an entrainment filter. The secondary ribs may comprise a solid member, or may comprise a row of tabs or bristles. The secondary rib may incidentally serve to protect the reflective surface 108 from damage. The damage may originate from a vehicle traversing over the marker or other environmental hazards that may be encountered.
In one embodiment, the point of intersection of the base and the stand is a living hinge. In another embodiment, the entire stand is flexible. Independent of the material used to construct the temporary flexible pavement markers, the markers may be configured such that when they are run over by an automobile, the material will rebound substantially to its original configuration so that the reflective surface will be visible to drivers.
In other embodiments, as may be seen in
As may be seen in
The width of the protective shield may be configured to optimize spray protection of the reflective surface without substantially interfering with visibility of any reflective material and on the associated face of the marker. Similarly, the width of the secondary rib may be configured to optimize spray back splash protection of the reflective surface without substantially interfering with visibility of any reflective material and on the associated face of the marker.
Thus, a protective shield may be provided in a variety of configurations. For embodiments comprising a protective shield extending substantially perpendicularly from the stand (such as in
Similarly, a secondary rib may be provided in a variety of configurations. In some embodiments, a secondary rib may extend about 0.09 inches from the face of the stand. The secondary rib may be disposed at or near the edge of any reflective surface opposite the protective shield. The width or amount of extension from the stand by the secondary rib may be dependent on typical angles at which spray may be discharged from a spray nozzle. For example, fluid may be sprayed from a nozzle in a conical or fan shaped pattern. A secondary rib may, in some embodiments, be about 0.02 inches thick and about 0.09 inches wide.
For example, with reference to
A temporary pavement marker may be provided in a variety of other configurations. For example, the marker 100 of
In some embodiments, a one-sided temporary pavement marker may be provided. For example, as may be seen in the embodiment of
Similarly, as may be seen in the embodiment of
In some embodiments, a secondary rib need not be used if the road surface will be sprayed at a pressure and height that will not substantially result in backsplash of spray from the road. In the embodiment of
The temporary flexible pavement markers of the application may be prepared using any material known to be useful to those of ordinary skill in the art of making such items. For example, they may be prepared using plastics and/or metal. When the markers are made of plastic, the plastic used maybe one selected from the group consisting of: polyethylene, polypropylene, polyurethane, polyvinyl chloride, copolymers of polyethylene and polypropylene, and combinations thereof. Other plastics may also be used. Biodegradable materials of various types may be used. Useful metals include, but are not limited to, aluminum, spring steel, and the like. In some embodiments, the markers may be prepared using composites of metal and plastics. Various portions of the marker portions, such as base, stand, protective shield and secondary rib, may be sufficiently thick so as to permit the stand to substantially maintain shape under a variety of road conditions sufficient for the reflective surface thereof to reflect the headlights of vehicles traveling on the road, such as for roads situated in icy or desert conditions, and to substantially return to such shape if deformed by a passing vehicle or extreme road condition.
The reflective surface of the stand may cover a majority of the surface area of the stand, or a substantial portion thereof (such as in
The dimensions of the temporary flexible pavement markers of the application may be any that are useful for delineating traffic lanes. In some embodiments, the markers are about 4 inches wide and about 2 inches high. In these embodiments, a base in the “L” configuration may be from about 1 to about 2 inches wide while a base in a “T” configuration may be from about 1.5 to about 4 inches wide. In many venues, the governmental entity having responsibility for the maintenance and construction of highways may have a specification governing such dimensions.
The protective shield of the temporary flexible pavement markers disclosed herein are integral to the marker (whether securely affixed thereto or forming a unitary article of manufacture therewith), and are configured to be non-removable from the stand. The purpose of this protective shield is to prevent or at least mitigate fluids such as asphalt, tar, or oil from obscuring the reflective surface of the stand during spraying. As noted above, such spraying may occur both in initial construction and in repairing roads. Accordingly, the protective shield may take a variety of suitable configurations according to the teachings hereof. For example, the protective shield edge 800 of the marker may be, as noted above, squared, curved, or chamfered, filleted or tapered, or provided with a radius, or any combination thereof, as may be seen in the embodiments of
It will also be appreciated that various marker embodiments shown herein are depicted in design form, and that various imperfections may exist in such markers as actually mass manufactured. For example, depending on the composition of the marker and method of manufacturing, a marker manufactured to have a tapered protective shield according to the embodiment of
During the repair or construction of a road, a subsurface is first prepared. Often asphalt is applied and then gravel is spread upon the road subsurface and fixed in place by the asphalt. In one embodiment of the method of the application, a temporary flexible pavement marker is placed upon the subsurface, next a spray of asphalt is applied (as shown in
The asphalt spraying procedure is comparatively slow which results in the asphalt or other sealer being sprayed nearly straight down. Some of the figures show that the protective shield is angled down. In alternative embodiments, the orientation of the protective shield may be substantially perpendicular to the stand. The width of the protective shield, for a 4-inch by 2-inch temporary pavement marker, may thus be from ½ to 1 inch. These dimensions may be scaled or otherwise adjusted for temporary flexible pavement markers having different overall dimensions.
The temporary flexible pavement markers of the application may be configured to be reflective on one side or two sides. Reflective surfaces may be, for example, white, amber or silver. The markers reflective on one side would be useful for one-way traffic while the markers being reflective on both sides could be used for two-way traffic. It is also within the scope of the application that the markers be color coded in accordance with local ordinances to indicate one-way or two-way traffic, divisions between lanes, edges of lanes, and other traffic control information. For example, for one-way traffic, the marker could be white and for two-way traffic, yellow.
The temporary flexible pavement markers of the application represent a substantial improvement over the prior art. Prior art markers included one or more clear protective layers that had to be removed after a spraying operation. In practice, a crew of laborers would, prior to any asphalt spray work, lay down the temporary pavement markers to delineate traffic lines. For road repair, temporary pavement markers may be laid down over the top of the existing traffic lines. Typically, this is done in a coded fashion to indicate the existence of solid and broken traffic lines, turn lanes, and other traffic markings. One or more other layers of clear protective covering may be left in place on prior art markers. Since the layers of protective covers were clear, oncoming traffic could clearly see the reflective surfaces on the temporary pavement marker.
In a typical asphalt seal operation, a coating of liquid asphalt would be applied to the pavement which would coat the pavement and the reflective surfaces of the prior art temporary road markers, thereby obscuring the reflective portion of each temporary pavement marker. If the road were open during construction, the reflective surface of the markers would not serve to indicate—particularly at night—the location of the markers. Therefore, in order to restore the reflective properties of the temporary pavement markers, laborers would walk along the road from one temporary pavement marker to the next, stopping at each to remove the clear cover (or for markers with multiple clear protective layers, the outermost protective cover) in order to reveal the reflective properties of the temporary pavement markers, both for the safety of motorists and to serve as a guide for the paint truck that is soon to follow. This is a labor intensive, time consuming, and therefore expensive operation. For example, if this were to be done during a typical highway resurfacing of a portion of highway approximately eight miles long, it would take a crew of two people, each working from opposite ends of the resurfacing project and walking inward, approximately eight hours to stoop down and peel off so as to manually remove one protective coating from each of the temporary pavement markers along the entire eight miles. In addition to the time and cost of peeling off protective layers, removing such layers exposed laborers to traffic safety hazards.
In such situations, a technician was required to bend down or bend over to remove the protective layer from each marker. Since the number of markers employed in such operations may range from 500 to several thousand per mile, the cost for this was not insignificant. Placing the laborers in a slow-moving vehicle from which they might reach down and remove the protective cover might save some time and increase worker safety, but still such task had to be done.
Thus, a substantial advantage of the disclosed protective shield is that a temporary pavement marker may be provided without a protective cover, clear or otherwise, requiring removal. By providing a protective shield configured to substantially prevent asphalt or oil spray from obscuring the reflective surface, the need for the step of removing protective covers is eliminated. Furthermore, the temporary construction of the markers permits the stand to break off from the base over time (e.g., 45 days) after application of sufficient environmental stress, such as UV light and traffic impact.
In addition to the elements that are described, the temporary flexible pavement markers of the application may be prepared with any additional element known to be useful to those of ordinary skill in the art of making such objects. For example, in one embodiment, the temporary flexible pavement markers may have an adhesive applied to the bottom of the base. In most applications, the adhesive is a tacky adhesive and is protected from getting dirty by use of a paper or plastic tape. Thus, although the disclosed subject matter and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition, or matter, means, methods and steps described in the specification. As one will readily appreciate from the disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, systems or steps.
This application is a continuation of U.S. Non-Provisional patent application Ser. No. 15/668,154 entitled “Temporary Flexible Pavement Markers” filed Aug. 3, 2017, which is a continuation-in-part of U.S. Non-Provisional patent application Ser. No. 14/654,278 entitled “Temporary Flexible Pavement Markers” filed Jun. 19, 2015, which is a national stage entry under 35 U.S.C. 371 of International Patent Application No. PCT/US2013/076558 entitled “Temporary Flexible Pavement Markers” filed Dec. 19, 2013, which claims priority to U.S. Provisional Patent Application 61/749,058, entitled “Temporary Flexible Pavement Markers” filed Jan. 4, 2013, each of which are hereby entirely incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61749058 | Jan 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15668154 | Aug 2017 | US |
| Child | 17978891 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14654278 | Jun 2015 | US |
| Child | 15668154 | US |
